GB331256A - Improvements in or relating to devices for producing or restoring synchronism as between the projector and the gramophone of a talking-picture machine - Google Patents

Abstract

331,256. Hepworth, C. M. March 27, 1929. Gramophones associated with kinematographs. - Relates to talking-picture apparatus comprising a synchronously working gramophone and kinematograph, and consists of a particular arrangement of mechanism, embodying epicyclic gearing, whereby errors of phase may be corrected, such errors being caused, for example, by the gramophone needle jumping out of proper position on the record groove. In the system shown in Fig. 1, a gramophone 11 and a kinematograph projector 10 are driven by a common motor 12. The connection between the motor and the projector comprises two shafts 14, 15 coupled by a pair of epicyclic gear trains as shown in Fig. 3. Each of these trains consists of two wheels 19, 20 of slightly different diameter, gearing respectively with coaxial pinions 21, 22 fixed on a shaft 24 which is mounted in a casing 18. Normally the casings 18 rotate solidly with the shafts 14, 15 and the intermediate shaft 23. If, however, it is necessary at any time to speed up or retard the projector relatively to the gramophone, one of the casings 18 is gripped by hand, thus causing the gears associated with that casing to alter the speed of the driven shaft. The two gear trains are similarly constructed, but the wheels are oppositely arranged, so that the effect produced by gripping one casing is the opposite of that produced by holding the other. The invention may be applied, as shown in Fig. 2, to a system in which a speed-equalizing rheostat 26 - - 28 is used in conjunction with two separately driven machines 10, 11, as described in Specification 324,005. A flexible coupling device 29 may also be provided in this arrangement, as described in Specification 325,882.